600+rwhp Automatic Infiniti G37 Sedan

“I want it to scare me” were the words that came out of Mark’s mouth when he returned to our shop 6 months after his initial build to upgrade the supercharger pulley and a few other components. Mark was fairly new to forced induction towards the beginning of the year, however it didn’t take long for him to get used to the power of the supercharger kit on 9 psi and decided it was time for more. Fast forward to a few weeks ago when mark brought his immaculate Infiniti G37 back up to have a pair of Z1 motorsports headers and Fast Intentions resonated test pipes installed along with the 9 psi pulley to his air to air supercharger kit. The biggest change from the prior visit was that the vehicle now had the Motordyne engineering TDX exhaust instead of the fast intentions catback exhaust.

The biggest obstacle that we would face would be how far we would be able to take the stock automatic transmission and stock flex plate. Previously the car made 531 rwhp and 398 ft-lbs of torque and with just over 1800 miles on this setup the transmission was still in good shape.

The Z1 Motorsports headers fit perfectly in the engine bay and looked great as well with ceramic coating applied from Calico Coatings. In order for the VQ35DE headers from Z1 Motorsports to work on the VHR engine, we had to order Infiniti G35 resonated test pipes to allow for it to mate to the G37 Motordyne engineering TDX exhaust system. With these components installed and the initial startup, all we could say was “wow!” – this did not sound like a regular VQ – it had a very exotic and unique tone to it. There was two more modifications that we needed to make prior to getting the vehicle on the dyno, which included the installation of the 9 psi pulley and replacing the injector dynamic 750cc injectors with 1300cc injectors as the new setup would be maxing out the relatively small 750cc injectors very quickly with the increased boost levels.

With the additional components installed it was now time to hit the dyno with hopes of breaking the 600 rwhp mark. However after the first pull we had run into a minor fuel pressure issue but with air fuel safety custom mapping incorporated into the ecutek tune, the throttle closed to prevent the engine from any damages due to the lean condition.

On the initial install of the supercharger kit we used a Walbro 450 fuel pump as we wanted to ensure the car would have enough fuel pump to handle the boost levels that we were expecting to see. However, the Infiniti G37 sedan is the only VHR vehicle that CJM does not offer a twin pump assembly for and with that in mind we knew that if we were ever to run out of fuel pump that we might have to incorporate an external fuel pump. Luckily, Walbro was one step ahead of us and had just released their new “Hellcat” 520 fuel pump that would increase the flow from 450lph to 525 lph which was going to be enough for us at this point.

With a very promising dyno graph showcasing a 600+ end horsepower target, we knew that we were pushing the limitations of the stock transmission and flex plate above and beyond what anybody would have imagined and it was time to contact Mark to inform him that now would be a good time to upgrade the transmission. Mark had an idea that the transmission would need to upgraded and had been talking with Pat at level 10 and a few days later a “1000 hp” built transmission arrived at our doorstep.

With the upgraded transmission ready for installation we also upgraded the stock flex plate to the Fast intentions flex plate as seen below.

With peace of mind that the stock transmission was not going to fail, we installed the new Walboro 525 hellcat pump into the stock fuel pump basket and strapped the car back on the dyno with confidence that we would be able to hit our initial goal of 600+ rwhp and be able to deliver a car that would “scare” Mark.

Mission Accomplished!

Contact us to inquire about a build very similar to this or any build that you may have in mind! Below is a short video clip of the car on the dyno and man is it a handful on the street 🙂